Touchscreen-enhanced visual learning in rats

The efficiency of traditional levers and of modern touchscreen technology for training rats on a computerized visual discrimination was studied in a series of observations. When compared with a lever-based discrimination procedure, the use of touchscreens supported the faster development of signal tracking behavior and acquisition of a two-stimulus simultaneous visual discrimination. It did not affect the final level of accuracy. Factors related to spatial proximity of the responses with the stimuli, sign-tracking, and increased ease of touchscreen motor responses were suggested as possible reasons for the touchscreen training advantage. This increased efficiency allows large numbers of animals to be tested quickly, a necessary requirement for studies involving genetic and physiological interventions.     

Perceptions of Ethical Behaviour among Business Faculty in Canada

Faculty members at Canadian business schools were surveyed regarding their ethical perceptions of behaviours related to undergraduate instruction. Fifty-five behavioural statements were listed and respondents were asked to rate the extent to which they felt each behaviour was ethical or unethical. The only item that respondents endorsed as unequivocally unethical (90% indicated it was definitely unethical) was Becoming sexually involved with an undergraduate in one of your classes. We also compared the results of our sample to those of an American sample. Overall, an interesting pattern of differences emerged between the responses obtained in Canada and the U.S. In general, the direction of the significant differences was such that Canadian professors viewed the behaviours in question as less ethical than did their American counterparts.     

Changes in adolescent response patterns on the MMPI/MMPI--a across four decades

The purpose of this study was to explore changes in adolescent self-presentation on the Minnesota Multiphasic Personality Inventory (MMPI; Hathaway & McKinley, 1940) and MMPI-A (Butcher et al., 1992) over a 40-year period. The primary samples used for comparison in this study include 1,235 adolescents, age 14 through 16, derived from the MMPI-A normative sample (Butcher et al., 1992) collected in 1989 and 10,514 adolescents, age 14 through 16, collected in 1948 and 1954 from Hathaway and Monachesi's (1963) study of adolescent personality and behavior. MMPI basic scale and item-level data were also included for 817 adolescents, age 14 through 16, collected by Colligan and Offord (1992) in 1985 as a further comparison. Between-sample analyses at the profile level revealed that adolescents from the MMPI-A normative sample scored significantly higher across basic clinical scales and lower on validity scales L and K than adolescents from the Hathaway and Monachesi (1963) sample, with mean data from the Colligan and Offord (1992) sample typically falling at a midpoint value. Analyses of Harris-Lingoes (Harris & Lingoes, 1955) subscale and item-level data were conducted to provide refined definitions of the contents of scale-level changes. Results were interpreted as reflecting moderate to large changes in response frequencies between eras of data collection, and emphasis was placed on the relatively high frequency of item endorsements by contemporary adolescents in the clinical direction in the MMPI-A normative sample. A series of cautions and limitations are also offered in interpreting these patterns.     

MMPI-2 L + K and L + K - F indexes of underreporting: normative and desirable responding

Norms based on the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) normative sample are provided for the L + K and L + K - F indexes of underreporting and defensiveness. Index scores produced by consistently desirable responding, which was guided by desirability ratings of the MMPI-2 items, also are provided and compared with scores produced by underreporting in other studies. The indexes correlate highly with other measures of underreporting in both normative and clinical samples. The L and K scales assess different types of underreporting and should be interpreted separately as well as in combination. The L scale can be elevated by undesirable responding or random responding in addition to desirable responding.     

An evaluation of the effects of Rorschach EB style on the diagnostic utility of the Depression Index

Several empirical studies have found the Rorschach Depression Index (DEPI) to have questionable diagnostic utility. Studies using adolescent samples suggest that the DEPI has limited sensitivity and fails to differentiate effectively between adolescents with and without depression diagnoses. The present study was conducted to evaluate Viglione, Brager, and Haller's suggestion that the DEPI may have better discriminative ability for individuals with extratensive problem-solving styles, measured by the Rorschach EB (Erlebnistypus) variable, compared to those with introversive and ambitent styles. Comparisons were conducted between adolescents with depression-related diagnoses and adolescents with other diagnoses for each of the three EB groups. The results failed to support the hypothesized greater discriminative power of DEPI for depressed extratensives, and suggest caution in using the DEPI to evaluate adolescent depression.     

Visual perspective taking for avatars in a Simon task

In modern digital applications, users often interact with virtual representations of themselves or others, called avatars. We examined how these avatars and their perspectives influence stimulus–response compatibility in a Simon task. Participants responded to light/dark blue stimuli with left/right key presses in the presence of a task-irrelevant avatar. Changes in stimulus–response compatibility were used to quantify changes in the mental representation of the task and perspective taking toward this avatar. Experiments 1 and 2 showed that perspective taking for an avatar occurred in orthogonal stimulus–response mappings, causing a compatibility effect from the avatar’s point of view. In the following two experiments we introduced a larger variety of angular disparities between the participant and avatar. In Experiment 3, the Simon effect with lateralized stimulus positions remained largely unaffected by the avatar, pointing toward an absence of perspective taking. In Experiment 4, after avatar hand movements were added in order to strengthen the participants’ sense of agency over the avatar, a spatial compatibility effect from the avatar’s perspective was observed again, and hints of the selective use of perspective taking on a trial-by-trial basis were found. Overall, the results indicate that users can incorporate the perspective of an avatar into their mental representation of a situation, even when this perspective is unnecessary to complete a task, but that certain contextual requirements have to be met.     

Evaluation of an MMPI--a short form: implications for adaptive testing

Efforts to develop a viable short form of the MMPI (Hathaway & McKinley, 1943) span more than 50 years, with more recent attempts to significantly shorten the item pool focused on the use of adaptive computerized test administration. In this article, we report some psychometric properties of an MMPI-Adolescent version (MMPI-A; Butcher et al., 1992) short form based on administration of the first 150 items of this test instrument. We report results for both the MMPI-A normative sample of 1,620 adolescents and a clinical sample of 565 adolescents in a variety of treatment settings. We summarize results for the MMPI-A basic scales in terms of Pearson product-moment correlations generated between full administration and short-form administration formats and mean Tscore elevations for the basic scales generated by each approach. In this investigation, we also examined single-scale and 2-point congruences found for the MMPI-A basic clinical scales as derived from standard and short-form administrations. We present the relative strengths and weaknesses of the MMPI-A short form and discuss the findings in terms of implications for attempts to shorten the item pool through the use of computerized adaptive assessment approaches.     

A comparison of two interpretive approaches for the MMPI--A Structural Summary

We undertook this study to provide empirically derived interpretative recommendations for the MMPI-A Structural Summary through an evaluation of factor elevation patterns. We examined the frequency of single-factor, two-factor, and multifactor elevations in a clinical sample of 363 adolescents receiving inpatient, outpatient, or residential treatment. Two methods of determining factor elevation (a simple majority of scales and subscales within a specific factor with T-score elevations at critical level, versus the mean T score generated by all the scales and subscales for each factor) yielded comparable findings concerning the frequency of factor elevation, permitting reliance on the former, easier-to-use method to define elevation. The most salient two-factor co-elevations were the 3-7 (Disinhibition-Familial Alienation), 2-8 (Immaturity-Psychoticism), 1-5 (General Maladjustment-Health Concerns), and 2-7 (Immaturity-Familial Alienation) patterns. This study also examined whether factor pattern elevations varied as a function of age, gender, or diagnosis. Data analyses revealed no differences between younger (ages 13-14) and older (ages 15-18) adolescents on factor elevation as defined by the first criterion. However, significant differences were found between boys and girls on Factors 3 (Disinhibition) and 5 (Health Concerns). Results also indicated that a larger proportion of depressed adolescents obtained factor elevations on Factors 4 (Social Discomfort) and 5 (Health Concerns) compared to adolescents with conduct disorder diagnoses and other diagnoses. The findings of this study are discussed with reference to recommended procedures for using the Structural Summary in clinical assessment practice.     

Identification of random responding on the MMPI-A

Although substantial research literature on the effects of random responding on the MMPI-2 exists, there is very limited data available on this issue with the MMPI-A. The purpose of this study was to evaluate the utility of selected MMPI-A validity scales in detecting differences in response patterns between protocols produced by 354 adolescents assessed in clinical settings and a group of 354 randomly produced MMPI-A protocols. Results indicate that MMPI-A validity and basic clinical scales differ significantly between random and clinical groups and that MMPI-A validity Scales F, F1, F2, and VRIN appear to be most useful in correctly identifying protocols from actual clinical participants versus randomly generated response patterns. Findings are discussed in terms of the dramatic effects of the sample base rate for random responding on overall classification accuracy results. Furthermore, it was noted that the optimal cutting scores for MMPI-A Scales F, F1, F2, and VRIN were largely consistent with interpretive recommendations found in the test manual (Butcher et al., 1992) when the relative frequency of random response protocols to clinical protocols was evaluated at a ratio of 1:10. Finally, future recommendations for evaluation of the F1-F2 difference score and the TRIN scale are offered in terms of the most relevant research designs to evaluate these measures.     

Knowledge level learning and the power law: A soar model of skill acquisition in scheduling

Zusammenfassung. Das hier vorgestellte Modell lernt graduell, Planungsaufgaben aus der Klasse der Maschinenbelegungsprobleme (job-shop-scheduling problems) zu lösen. Mit Hilfe des Chunking-Mechanismus von Soar wird episodisches Wissen über die Belegungsreihenfolge von Aufträgen auf Maschinen memoriert. Bei der Entwicklung des Modells wurden zahlreiche qualitative (z. B. Transfereffekte) und quantitative Befunde (z. B. Bearbeitungszeiten) aus einer früheren empirischen Untersuchung berücksichtigt. In einer Validierungsstudie wurden dieselben Aufgaben von 14 Probanden und dem Modell bearbeitet. Die Passung von Simulationsdaten und empirischen Ergebnissen fiel insgesamt gut aus. Allerdings löst das Modell die Aufgaben schneller und zeigt auch einen etwas besseren Lernverlauf als die Probanden. Das Modell liefert eine Erklärung für das Rauschen, das typischerweise bei Bearbeitungszeiten zu beobachten ist: es handelt sich um erworbenes Wissen, das mehr oder weniger gut und auch unterschiedlich häufig auf neue Situationen übertragen wird. Der Lernverlauf der Probanden entspricht nur für aggregierte Daten einer Potenzfunktion (power law). Der vorgestellte Mechanismus zeigt, wie ein symbolisches Modell der Informationsverarbeitung graduelle Verhaltensänderungen generiert und wie der offensichtliche Erwerb allgemeiner Prozeduren ohne explizites Lernen von deklarativen Regeln erfolgen kann. Es wird nahegelegt, daß es sich hier um die Modellierung einer Form impliziten Lernens handelt. Summary. The model presented here gradually learns how to perform a job-shop scheduling task. It uses Soar's chunking mechanism to acquire episodic memories about the order to schedule jobs. The model was based on many qualitative (e.g., transfer effects) and quantitative (e.g., solution time) regularities found in previously collected data. The model was tested with new data where scheduling tasks were given to the model and to 14 subjects. The model generally fit these data with the restrictions that the model performs the task (in simulated time) faster than the subjects, and its performance improves somewhat more quickly than the subjects' performance. The model provides an explanation of the noise typically found in problem solving times - it is the result of learning actual pieces of knowledge that transfer more or less to new situations but rarely by an average amount. Only when the data are averaged (i.e., over subjects) does the smooth power law appear. This mechanism demonstrates how symbolic models can exhibit a gradual change in behavior and how the apparent acquisition of general procedures can be performed without resorting to explicit declarative rule generation. We suggest that this may represent a type of implicit learning.